There are conventional sealing structures shown in FIGS. 8A to 10B as a sealing structure for an opening which is closed with a cap of a fuel tank for the vehicle with, for example, four wheels.
FIGS. 8A to 10B are cross section views each showing a main part of the conventional sealing structure between a cap of a fuel tank and a fuel tank body.
For example, as shown in FIGS. 8A and 8B, there are sealing structures in which thread parts 101na, 101nb are formed in blow molding of the fuel tanks 101a, 101b made of resin to provide clamping with lock nuts 104a, 104b made of resin (occasionally, metal) through packing 102a, 102b and parts 103a, 103b (in frequent cases, a pump module for suspending a pump for pumping fuel), respectively.
Alternatively, as shown in FIG. 9, there is a sealing structure in which a separated part 206 having a thread part is attached to a fuel tank 201, after the blow molding, made of resin to clamp with a lock nut 204 through a packing 202 and a part 203 such as a pump module, etc.
Alternatively, as respectively, shown in FIGS. 10A and 10B, during blow molding of fuel tanks 301a, 301b made of resin, metal plates 304a, 304b are subjected to insert molding, and sealing is provided by compressing packing 302a, 302b with metal retainers 305a, 305b through the packing 302a, 302b and parts 303a, 303b such as the pump module. This is so-called cam-lock.
For example, there are patent documents regarding the sealing structures of the fuel tank, i.e., Patent documents 1, 2.